Tilted printed circuit board installation

ABSTRACT

A blade for a chassis-based system includes a printed circuit board (PCB) mounted at a tilt angle within the blade. The tilt angle provides space above or below the PCB at the front end of the blade, such that media interface modules can be flexibly positioned within the blade. A tilt angle that positions the PCB higher near the front end of the blade may enable media interface modules mounted in a belly-to-belly configuration on the PCB to be fitted within the front end of the blade. A tilt angle that positions the PCB lower near the front end of the blade may enable media interface modules mounted on the upper surface of the PCB to be fitted within the first end of the blade. The tilt angle also positions a backplane connector mounted on the PCB to properly engage a backplane when the blade is inserted into a slot.

FIELD OF THE INVENTION

The present invention relates to a blade used in a chassis-based system.More specifically, the present invention relates to the tiltedinstallation of a printed circuit board within a blade.

RELATED ART

FIG. 1A is an isometric view of a conventional rack-mountable blade 100,which includes blade pan assembly 101, printed circuit board (PCB) 102,blade hardware 103-104, media interface module 105, PCB mountingstructures 106-108 and high density backplane connector 109. FIG. 1B isa cross-sectional view of blade 100 along section line B-B of FIG. 1A.FIG. 1B also illustrates a portion of a chassis 120 having an associatedslot 121 for receiving blade 100, along with a portion of a backplane130, which is coupled to chassis 120, and a high density backplaneconnector 131, which is coupled to backplane 130.

Blade pan assembly 101 includes a flat bottom portion 101A, and anupright faceplate portion 101B. Blade pan assembly 101 is typicallyformed from sheet metal. PCB 102 is attached to the flat bottom portion101A of blade pan assembly 101 by PCB mounting structures 106-108. Asillustrated in FIG. 1B, each of the PCB mounting structures has the samefixed height H1, such that PCB 102 is positioned a fixed height H1above, and in parallel with, the flat bottom portion 101A.

Blade hardware 103 and 104 includes integrated circuit chips, discretecircuit elements (e.g., resistors and capacitors), heat sinks and/orinterconnect structures, which are located on the upper and lowersurfaces of PCB 102, respectively. As described below, the height of theupper blade hardware 103 is greater than the height of the lower bladehardware 104.

Media interface module 105 is attached to the upper surface of PCB 102.The media interface module 105 can be fixed (as described herein) orpluggable (wherein module 105 is a connector on PCB 102). Mediainterface module 105 is coupled to electronic circuitry in bladehardware 103/104 by conductive traces in PCB 102. A portion of mediainterface module 105 is exposed through an opening 101C in the faceplateportion 101B of blade pan assembly 101. The exposed portion of mediainterface module 105 includes a port structure that allows for theconnection of a network cable (e.g., an Ethernet cable, or an opticalcable).

High density backplane connector 109 is attached to the upper surface ofPCB 102, at the end opposite media interface module 105. High densitybackplane connector 109 includes a plurality of connector elements(represented by dashed lines in FIG. 1B) that are connected toconductive traces on PCB 102 and extend to a back end 109A of highdensity backplane connector 109.

Blade 100 is inserted into slot 121 within a chassis 120. Note that thisslot 121 is typically defined by side support elements of chassis 120(not shown), which engage lateral edges of the blade pan assembly 101. Abackplane 130 is attached to the chassis 120. Backplane 130 includeselectrical pathways that allow different blades in chassis 120 tocommunicate. A high density backplane connector 131 is attached tobackplane 130 at a predetermined fixed location within slot 121.High-density backplane connector 131 is configured to engage with highdensity backplane connector 109 (i.e., in a plug/socket configuration)when blade 100 is fully inserted into slot 121. Once engaged, the highdensity backplane connectors 109 and 131 provide electrical connectionsbetween PCB 102 and backplane 130.

One of the design considerations associated with blade 100 is the slotheight H. It is desirable to minimize the slot height H_(S) in order tomaximize the number of blades that can fit in a chassis. Another designconsideration associated with blade 100 is the location of particularcircuit elements on PCB 102. Shorter, cool-operating passive parts aretypically located on the lower surface of PCB 102 (i.e., blade hardware104), and taller, hot-operating active parts are typically located onthe upper surface of PCB 102 (i.e., blade hardware 103). In order tominimize the height of blade 100 (and therefore the required slot heightH_(S)) PCB 102 is positioned at a height H1 that is relatively close tothe flat bottom portion 101A of blade pan assembly 101. Note thatpositioning PCB 102 at the middle of the slot height H_(S) is notoptimal (because such positioning would undesirably, and unnecessarily,increase the required slot height).

The height H1 is insufficient to allow a conventional media interfacemodule (e.g., media interface module 105) to be mounted under theprinted circuit board 102. That is, the height of a conventional mediainterface module is greater than the distance H1 that exists between thelower surface of PCB 102 and the upper surface of the flat bottomportion 101A of pan blade assembly 101. As a result, blade 100 isundesirably limited to a single row of media interface ports 105 acrossthe faceplate portion 101B of blade pan assembly 101. (See, FIG. 1A.)

FIG. 2 is a cross-sectional view of another conventional rack-mountableblade 200, which allows two rows of media interface ports to be locatedat the front surface of blade 200. Blade 200 includes blade pan assembly201, media interface modules 205-206, high-density backplane connector209, PCB (motherboard) 210, motherboard hardware 211-212, motherboardmounting structures 213-215, PCB (daughterboard) 220, daughterboardhardware 213-214, daughterboard mounting structures 223-224, and bridgestructure 230. Blade pan assembly 201 includes flat bottom portion 201Aand upright faceplate portion 201B. Motherboard 210 and daughterboard220 replace the single PCB 102 of blade 100. Motherboard hardware 211and daughterboard hardware 221 roughly corresponds with blade hardware103 of blade 100 (although daughterboard hardware 221 is typicallydesigned to have a smaller height than motherboard hardware 221, suchthat the overall height of slot 121 does not have to be increased inview of the height of daughterboard 220). Similarly, motherboardhardware 212 and daughterboard hardware 222 roughly corresponds withblade hardware 104 of blade 100.

Motherboard 210 is attached to the flat bottom portion 201A of blade panassembly 201 by mounting structures 213-215. As illustrated in FIG. 2,each of the mounting structures 213-215 has the same fixed height H1 asPCB mounting structures 106-108 (FIG. 1B), such that motherboard 210 ispositioned a fixed height H1 above, and in parallel with, the flatbottom portion 201A. As a result, high-density backplane connector 209of blade 200 is positioned in the same manner as high-density backplaneconnector 109 of blade 100. As a result, high-density backplaneconnector 209 properly engages high-density backplane connector 131 onbackplane 130 when blade 200 is inserted into slot 121.

Daughterboard 220 is attached to the flat bottom portion 201A of bladepan assembly 201 by mounting structures 223-224. As illustrated in FIG.2, each of the mounting structures 223-224 has the same fixed height H2,wherein height H2 is greater than height H1. The height H2 is selectedsuch that media interface module 205 may be attached to the uppersurface of daughterboard 220, and media interface module 206 may beattached to the lower surface of daughterboard 220, as illustrated. Thatis, media interface modules 205 and 206 are connected in abelly-to-belly configuration, on opposite sides of daughterboard 220. Asillustrated in FIG. 2, media interface modules 205 and 206 are exposedthrough openings 201C and 201D, respectively, in the faceplate portion201B of blade pan assembly 201. Because blade 200 allows two rows ofmedia interface modules to be implemented in a belly-to-bellyconfiguration, blade 200 may advantageously include twice as many mediainterface modules as blade 100.

However, the dissimilar heights of motherboard 210 and daughterboard 220necessitate the use of a bridge structure 230 between motherboard 210and daughterboard 220. Bridge structure 230 includes a plurality ofconductive paths, which enable signals to be transmitted betweenmotherboard 210 and daughterboard 220. Bridge structure 230 can include,for example, a high-speed connector and/or ribbon cable.

Blade 200 exhibits the following disadvantages with respect to blade100. Blade 200 will have higher materials costs than blade 100, becauseblade 200 requires an extra PCB (i.e., daughterboard 220), as well asthe additional hardware associated with the bridge structure 230. Blade200 will also have higher assembly costs, because blade 200 requires theinstallation of the extra PCB 220 and the bridge structure 230. Inaddition, signal integrity is degraded by the use of bridge structure230, which requires that signals be transmitted off of PCBs 210 and 220.The bridge structure 230 also creates a bottleneck for signalstransmitted between PCB 210 and PCB 220. The two-PCB structure of blade200 also results in less effective PCB area for components, ascomponents cannot be placed in the gap between PCB 210 and PCB 220.

It would therefore be desirable to have an improved blade structure,which allows the use of two rows of media interface modules (or largermedia interface modules), but does not exhibit the disadvantagesassociated with the motherboard/daughterboard design of blade 200.

SUMMARY

Accordingly, the present invention provides an improved blade, whichincludes a single printed circuit board mounted at a tilt angle within ablade pan assembly. The single printed circuit board extendssubstantially the entire depth of the blade (i.e., from the front end ofthe blade to the rear end of the blade). In one embodiment, the tiltangle causes the front end of the printed circuit board (i.e., the endof the printed circuit board located adjacent to the front end of theblade) to be positioned slightly higher than the rear end of the printedcircuit board (i.e., the end of the printed circuit board locatedadjacent to the read end of the blade). This configuration providesadditional space below the printed circuit board at the front end of theblade. This configuration allows media interface modules mounted in abelly-to-belly configuration at the front end of the printed circuitboard to be fitted into the front end of the blade.

In another embodiment, the tilt angle causes the front end of theprinted circuit board to be positioned slightly lower than the rear endof the printed circuit board. This configuration provides additionalspace above the printed circuit board at the front end of the blade.This configuration allows relatively tall media interface modulesmounted on the upper surface of the front end of the printed circuitboard to be fitted into the front end of the blade.

A high-density backplane connector may be mounted at the rear edge ofthe printed circuit board. In one embodiment, the tilt angle of theprinted circuit board is not large enough to prevent the high-densitybackplane connector from properly engaging a corresponding connectorelement on a backplane when the blade is inserted into a slot of achassis. In an alternate embodiment, a shim that exhibits the tilt angleis located between the printed circuit board and the high-densitybackplane connector, thereby leveling the high-density backplaneconnector. In another embodiment, a surface of the high-densitybackplane connector that is coupled to the printed circuit board isfabricated to exhibit the tilt angle, thereby leveling the high-densitybackplane connector.

The present invention will be more fully understood in view of thefollowing description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an isometric view of a conventional rack-mountable blade,which includes a single printed circuit board (PCB) and a single row ofmedia interface modules.

FIG. 1B is a cross sectional view of the blade of FIG. 1A along sectionline B-B of FIG. 1A.

FIG. 2 is a cross-sectional view of another conventional rack-mountableblade, which includes two PCBs and two rows of media interface modules.

FIG. 3 is a cross-sectional view of a rack-mountable blade in accordancewith one embodiment of the present invention.

FIG. 4A is a cross-sectional view of a high-density backplane connector,which is leveled by a shim, in accordance with one embodiment of thepresent invention.

FIG. 4B is a cross sectional view of a modified high-density backplaneconnector, which can be used in the blade of FIG. 3, in accordance withone embodiment of the present invention.

FIG. 4C is a cross sectional view of a modified high-density backplaneconnector having a tilted mating interface, which can be used in theblade of FIG. 3, in accordance with one embodiment of the presentinvention

FIG. 5A is a cross-sectional view of belly-to-belly media interfacemodules, which are aligned with a common vertical plane in accordancewith one embodiment of the present invention.

FIG. 5B is a cross-sectional view of belly-to-belly media interfacemodules, which are connected to a printed circuit board using shims inaccordance with one embodiment of the present invention.

FIG. 6 is a cross-sectional view of a rack-mountable blade in accordancewith an alternate embodiment of the present invention.

DETAILED DESCRIPTION

FIG. 3 is a cross-sectional view of a rack-mountable blade 300 inaccordance with one embodiment of the present invention. Blade 300includes blade pan assembly 301, printed circuit board (PCB) 302, bladehardware 303-304, media interface modules 305-306, PCB mountingstructures 307-309, and high-density backplane connector 310. FIG. 3also illustrates a chassis 120, slot 121, backplane 130 and high-densityinterconnect socket 131, which are described above in more detail inconnection with FIGS. 1A-1B and 2.

PCB 302 extends from the front edge of blade 300 to the rear edge ofblade 300, as illustrated. Blade hardware 303 and 304 is located on theupper and lower surfaces of PCB 302, respectively, as illustrated inFIG. 3. Blade hardware 303 and 304 may include, for example, integratedcircuit chips, discrete circuit elements (e.g., resistors andcapacitors), heat sinks and/or interconnect structures, which arelocated on the upper and lower surfaces of PCB 302, respectively. Ingeneral, blade hardware 303-304 performs the required processing withinblade 300. In the described embodiments, blade hardware 103 includes thetall, heat-generating parts of blade 300, while blade hardware 304includes short, cooler-operating parts. Consequently, the height ofblade hardware 304 is significantly less than the height of bladehardware 303.

Media interface modules 305 and 306 are mounted on the upper and lowersurfaces of PCB 302, respectively, in a belly-to-belly configuration. Asdescribed herein, a media interface module includes a socket and atransceiver, wherein the transceiver can be plugged into (or pulled outof) the socket. The socket is physically mounted to the PCB 302 and isdimensioned to receive the transceiver. The socket includes a connectorelement, which provides electrical connections between the transceiverand conductive traces of the PCB 302 (when the transceiver is pluggedinto the socket). The transceiver includes a port (e.g., and opticalport or an Ethernet port), which is exposed at the front end of blade300 when the transceiver is plugged into the socket. In the describedembodiments, media interface modules 305-306 are conventional modules,which are identical to media interface modules 105 (FIGS. 1A-1B) and205-206 (FIG. 2). Media interface modules 305-306 are coupled toelectronic circuitry in blade hardware 303/304 by conductive traces inPCB 302.

High-density backplane connector 310 is mounted on the upper surface ofPCB 302. High-density backplane connector 310, which is identical tohigh-density backplane connectors 109 (FIGS. 1A-1B) and 209 (FIG. 2) inthe present embodiment, includes electrical connections to PCB 302. Asdefined herein, media interface ports 305-306 are located at a frontedge of PCB 302, and high density connector plug 310 is located at arear edge of PCB 302.

Blade pan assembly 301 is substantially identical to blade panassemblies 101 (FIGS. 1A-1B) and 201 (FIG. 2). Thus, blade pan assembly301 includes a flat (planar) bottom portion 301A, which forms the bottomsurface of blade 300, and an upright faceplate portion 301B, which formsthe front surface of blade 300. Openings 301C and 301D, which extendthrough the faceplate portion 301B of blade pan assembly 301, exposemedia interface modules 305 and 306, respectively. Blade pan assembly301 is formed from sheet metal in the described embodiments, althoughblade pan assembly 301 can be formed of other materials in otherembodiments. PCB 302 is attached to the flat bottom portion 301A ofblade pan assembly 301 by PCB mounting structures 307-309. Asillustrated in FIG. 3, each of the PCB mounting structures 307-309 has adifferent height, such that PCB 302 is positioned at a slight angle withrespect to the flat bottom portion 301A. In the described embodiments,the PCB mounting structures 307, 308 and 309 have heights H_(A), H_(B)and H_(C), respectively, wherein H_(A)>H_(B)>H_(C). In a particularembodiment, the heights H_(A), H_(B) and H_(C) are selected such thatPCB 302 is positioned at a tilt angle A of about 0.86 degrees, withrespect to the flat bottom portion 301A of blade pan assembly 301.However, the tilt angle A can have other values in accordance with theguidance provided below. The tilt angle A depends on specific designtolerances, connectors used, PCB size, and whether the backplaneconnector 310 is shimmed (as described below).

The heights H_(A)-H_(C) of PCB mounting structures 307-309 are selectedsuch that the high-density backplane connector 310 is located at aheight that allows this connector 310 to properly engage with theassociated high-density backplane connector 131. The angle and heightswill vary depending on media interface type and particulars of the bladedesign. In one embodiment, the height of the rear edge of PCB 302 isapproximately equal to the height H1 (FIGS. 1B and 2). In thisembodiment, the high-density backplane connector 310 mounted on PCB 302is located at approximately the same height as the conventional highdensity backplane connectors 109 (FIG. 1B) and 209 (FIG. 2).Consequently, high-density backplane connector 310 will be properlyconnected to the corresponding high-density backplane connector 131 whenblade 300 is inserted into the slot 121 of chassis 120. Note that eventhough the high-density backplane connector 310 is at a slight angle(e.g., 0.86°) with respect to the flat portion 310A of pan bladeassembly 301, the tolerances of the high density backplane connectors310 and 131 are sufficient to allow these connectors 310 and 131 toproperly engage when blade 300 is inserted into slot 121. Stated anotherway, the tilt angle A is selected such that the insertion tolerances ofthe backplane connectors 310 and 131 are not exceeded.

When backplane connectors 310 and 131 are engaged, the tilt angle Aintroduces forces between the backplane 130 and PCB 302 (wherein theseforces tend to straighten the tilt of PCB 302). Thus, in designing blade300, all of these forces must be analyzed to ensure that no designallowances are exceeded.

FIGS. 4A and 4B are side views of high-density backplane connector 310and PCB 302 in accordance with alternate embodiments of the presentinvention. As illustrated in FIG. 4A, a shim 401 may be inserted betweenhigh-density backplane connector 310 and PCB 302, wherein the shim 401inclines the connector 310 by the angle A. As a result, shim 401 levelshigh-speed backplane connector 310, such that this connector 310 ispositioned in parallel with the flat bottom portion 301A of blade panassembly 301. In a particular embodiment, the thickest portion of shim401 is on the order of ten thousandths of an inch. Note that the shim401 is positioned at a location(s) where electrical connections betweenPCB 302 and high-density backplane connector 310 do not exist. Alternateembodiments may implement multiple shims between high-speed backplaneconnector 310 and PCB 302. In the embodiment of FIG. 4A, shim 401 mayintroduce forces between PCB 302 and backplane connector 310. Thus, indesigning blade 300, all of these forces must be analyzed to ensure thatno design allowances are exceeded.

As illustrated in FIG. 4B, the lower surface of high-density backplaneconnector 310 may be fabricated to have an angle that matches the tiltangle A of PCB 302. For example, a portion 402 of high-density backplaneconnector 310 may be removed by machining, or an equivalent process(i.e., connector 310 may simply be fabricated without portion 402).Eliminating portion 402 of high-density backplane connector 310advantageously levels this connector 310, thereby improving thealignment with high-density backplane connector 131.

As illustrated in FIG. 4C, the high-density backplane connector 310 maybe fabricated such that the mating interface within connector 310 issituated at the tilt angle A, with respect to the lower surface 310L ofconnector 310. Dashed line 410 illustrates the mating interface ofconnector 310 in accordance with one embodiment of the presentinvention. Positioning the mating interface of connector 310 at the tiltangle A promotes the alignment and connection of connector 310 withhigh-density backplane connector 131.

Returning now to FIG. 3, the heights H_(A)-H_(C) of PCB mountingstructures 307-309 are further selected such that the front edge of PCB302 is high enough to allow media interface modules 305 and 306 to bemounted in a belly-to-belly configuration on opposite sides of PCB 302.In one embodiment, the height of the front edge of PCB 302 isapproximately equal to the height H2 of daughterboard 220 in blade 200(FIG. 2). The tilt angle A of PCB 302 is selected to provide adequateclearance for media interface module 306 between PCB 302 and the flatbottom portion 301A of blade pan assembly 301, while also providingadequate clearance for media interface module 306 between PCB 302 andthe upper boundary of blade 300.

In the embodiment illustrated by FIG. 3, the front surfaces of mediainterface modules 305-306 co-planar, but are not located in parallelwith the vertical faceplate portion 301B of blade pan assembly 301.Rather, the front surfaces of media interface modules 305-306 are offsetfrom the plane of the faceplate portion 301B by the tilt angle, A. As aresult, media interface module 306 may protrude out through thefaceplate portion 301B slightly more than media interface module 305.

FIGS. 5A and 5B are cross sectional views of media interface modules305-306 and PCB 302 in accordance with alternate embodiments of thepresent invention. As illustrated in FIG. 5A, media interface module 305protrudes further past the front edge of PCB 302 than media interfacemodule 306. As a result, media interface modules 305 and 306 protrudeout through the faceplate portion 301B of blade pan assembly 301 by thesame amount. In this embodiment, the front surfaces of media interfacemodules 305 and 306 are not co-planar. However, the front surfaces ofmedia interface modules 305-306 are centered on a common vertical plane500. That is, the centers of the front surfaces of media interfacemodules 305-306 (which are shown by x's in FIG. 5A) are located on thesame vertical plane 500.

As illustrated in FIG. 5B, shims 501-502 may be inserted between mediainterface modules 305-306, respectively, and PCB 302. Shims 501-502level media interface modules 305-306, respectively, byinclining/reclining these modules by the tilt angle A. As a result,media interface modules 305-306 are positioned in parallel with the flatbottom portion 301A of blade pan assembly 301.

FIG. 6 is a cross-sectional view of a rack-mountable blade 600 inaccordance with an alternate embodiment of the present invention.Because blade 600 is similar to blade 300, similar elements are labeledwith similar reference numbers in FIGS. 3 and 6. Thus, blade 600includes blade pan assembly 301, PCB 302, blade hardware 303-304 andhigh-density backplane connector 310, which have been described above inconnection with FIG. 3. FIG. 6 also illustrates chassis 120, slot 121,backplane 130 and high-density interconnect socket 131.

PCB mounting structures 607-609 attach PCB 302 to the flat bottomportion 301A of blade pan assembly 301 in blade 600. PCB mountingstructures 607, 608 and 609 have heights H_(D), H_(E) and H_(F),respectively, wherein H_(D)<H_(E)<H_(F). As a result, PCB 302 ispositioned at a slight angle with respect to the flat bottom portion301A, wherein the front edge of PCB 302 is lower than the rear edge ofPCB 302.

Media interface module 605 is mounted on the upper surface of PCB 302,at the front edge of PCB 302. Media interface module 605 has a heightH_(M) that is greater than the heights of modules 105, 205-206 and305-306. In blade 600, the upright faceplate portion 301B of blade panassembly 301 is modified to include a relatively large opening 601C.This large opening 601C allows the relatively tall media interfacemodule 605 to be exposed through faceplate portion 301B.

The downward tilt angle A of PCB 302 is selected to allow the relativelyhigh media interface module 605 to be properly positioned at the frontsurface of blade 600. Note that without the downward tilt angle A, mediainterface module 605 would not fit within blade 600. (That is, thecombined heights of media interface module 605, PCB 302 and bladehardware 304, plus the required clearances, would be greater than theheight of the blade 600).

The exposed front surface of media interface module 605 is angledslightly downward in blade 600. In one embodiment, a shim may beinserted between media interface module 605 and PCB 302, therebyleveling media interface module 605 with respect to the flat bottomportion 301A of pan assembly 300. (See, e.g., FIG. 5B.)

The heights H_(D)-H_(F) of PCB mounting structures 607-609 are selectedsuch that the high-density backplane connector 310 is located at aheight that allows this connector 310 to properly engage with theassociated high-density backplane connector 131. The angle and heightswill vary depending on media interface type and particulars of the bladedesign. The design considerations associated with connector 310 havebeen described above in connection with FIGS. 3 and 4A-4B, and applyequally within blade 600. For example, the high-density backplaneconnector 310 of blade 600 can be shimmed or machined in the mannerdescribed above in connection with FIGS. 4A-4B. Note that the shim (ormachined) angle used in blade 600 would be reversed with respect toFIGS. 4A-4B.

Although the present invention has been described in connection withvarious embodiments, it is understood that variations of theseembodiments would be obvious to one of ordinary skill in the art. Forexample, although three PCB support structures 307-309 (or 607-609) areshown along the length of PCB 302, it is understood that two (or morethan three) PCB support structures can be used in alternate embodiments.Moreover, although PCB 302 has been described as being attached to thebottom portion 301A of pan assembly 301 by PCB support structures307-309, it is understood that PCB 302 could be mounted at the tiltangle A by attaching PCB 302 to other surfaces (e.g., side surfaces) ofpan assembly 301. Thus, the present invention is limited only by thefollowing claims.

We claim:
 1. A blade comprising: a pan assembly having a first planarportion that forms a bottom surface of the blade; a printed circuitboard coupled to the pan assembly, wherein the printed circuit board ismounted such that a non-zero tilt angle exists between the printedcircuit board and the first planar portion of the pan assembly; a firstblade hardware located on a first surface of the printed circuit board,wherein the first blade hardware exhibits a first height; a second bladehardware located on a second surface of the printed circuit board,opposite the first surface, wherein the second blade hardware exhibits asecond height that is less than the first height, and wherein theprinted circuit board is located between the first blade hardware andthe first planar portion of the pan assembly; a first media interfacemodule mounted on the second surface of the printed circuit board andexposed at a front end of the blade; a second media interface modulemounted on the first surface of the printed circuit board, wherein thesecond media interface module is exposed at the front end of the blade,wherein the non-zero tilt angle positions the printed circuit boardfarthest from the first planar portion of the pan assembly near thefront end of the blade.
 2. A blade comprising: a pan assembly having afirst planar portion that forms a bottom surface of the blade; a printedcircuit board coupled to the pan assembly, wherein the printed circuitboard is mounted such that a non-zero tilt angle exists between theprinted circuit board and the first planar portion of the pan assembly;a first blade hardware located on a first surface of the printed circuitboard, wherein the first blade hardware exhibits a first height; asecond blade hardware located on a second surface of the printed circuitboard, opposite the first surface, wherein the second blade hardwareexhibits a second height that is less than the first height, and whereinthe printed circuit board is located between the first blade hardwareand the first planar portion of the pan assembly; a first mediainterface module mounted on the second surface of the printed circuitboard and exposed at a front end of the blade; and a backplane connectormounted on the first surface of the printed circuit board, wherein thefirst media interface module is located at a first end of the printedcircuit board, and the backplane connector is located at a second end ofthe printed circuit board, opposite the first end of the printed circuitboard, and wherein the backplane connector is exposed at a rear end ofthe blade, opposite the front end of the blade.
 3. The blade of claim 2,wherein the non-zero tilt angle positions the second end of the printedcircuit board closer to the first planar portion of the pan assemblythan the first end of the printed circuit board.
 4. The blade of claim2, further comprising a first shim located between the backplaneconnector and the printed circuit board, wherein the shim positions thebackplane connector in parallel with the first planar portion of the panassembly.
 5. The blade of claim 2, wherein a mounting surface of thebackplane connector, which is mounted on the first surface of theprinted circuit board, exhibits the non-zero tilt angle, whereby thebackplane connector is positioned in parallel with the first planarportion of the pan assembly.
 6. A blade comprising: a pan assemblyhaving a first planar portion that forms a bottom surface of the blade;a printed circuit board coupled to the pan assembly, wherein the printedcircuit board is mounted such that a non-zero tilt angle exists betweenthe printed circuit board and the first planar portion of the panassembly; a first blade hardware located on a first surface of theprinted circuit board, wherein the first blade hardware exhibits a firstheight; a second blade hardware located on a second surface of theprinted circuit board, opposite the first surface, wherein the secondblade hardware exhibits a second height that is less than the firstheight, and wherein the printed circuit board is located between thefirst blade hardware and the first planar portion of the pan assembly; afirst media interface module mounted on the second surface of theprinted circuit board and exposed at a front end of the blade, whereinthe printed circuit board is located a first distance from the firstplanar portion of the pan assembly at the front end of the blade, and asecond distance from the first planar portion of the pan assembly at arear end of the blade, wherein the first distance is greater than thesecond distance.
 7. A blade comprising: a pan assembly having a firstplanar portion that forms a bottom surface of the blade; a printedcircuit board coupled to the pan assembly, wherein the printed circuitboard is mounted such that a non-zero tilt angle exists between theprinted circuit board and the first planar portion of the pan assembly;a first blade hardware located on a first surface of the printed circuitboard, wherein the first blade hardware exhibits a first height; asecond blade hardware located on a second surface of the printed circuitboard, opposite the first surface, wherein the second blade hardwareexhibits a second height that is less than the first height, and whereinthe printed circuit board is located between the first blade hardwareand the first planar portion of the pan assembly; a first mediainterface module mounted on the second surface of the printed circuitboard and exposed at a front end of the blade; a second media interfacemodule mounted on the first surface of the printed circuit board,wherein the second media interface module is exposed at the front end ofthe blade, wherein the pan assembly further comprises a faceplateportion located at the front end of the blade, wherein front surfaces ofthe first and second media interface modules are exposed through thefaceplate portion, wherein the front surfaces are co-planar with oneanother, but are not located in parallel with the faceplate portion. 8.A blade comprising: a pan assembly having a first planar portion thatforms a bottom surface of the blade; a printed circuit board coupled tothe pan assembly, wherein the printed circuit board is mounted such thata non-zero tilt angle exists between the printed circuit board and thefirst planar portion of the pan assembly; a first blade hardware locatedon a first surface of the printed circuit board, wherein the first bladehardware exhibits a first height; a second blade hardware located on asecond surface of the printed circuit board, opposite the first surface,wherein the second blade hardware exhibits a second height that is lessthan the first height, and wherein the printed circuit board is locatedbetween the first blade hardware and the first planar portion of the panassembly; a first media interface module mounted on the second surfaceof the printed circuit board and exposed at a front end of the blade; asecond media interface module mounted on the first surface of theprinted circuit board, wherein the second media interface module isexposed at the front end of the blade, wherein the pan assembly furthercomprises a faceplate portion located at the front end of the blade,wherein front surfaces of the first and second media interface modulesare exposed through the faceplate portion, wherein the front surfacesare not co-planar with one another.
 9. A blade comprising: a panassembly having a first planar portion that forms a bottom surface ofthe blade; a printed circuit board coupled to the pan assembly, whereinthe printed circuit board is mounted such that a non-zero tilt angleexists between the printed circuit board and the first planar portion ofthe pan assembly; a first blade hardware located on a first surface ofthe printed circuit board, wherein the first blade hardware exhibits afirst height; a second blade hardware located on a second surface of theprinted circuit board, opposite the first surface, wherein the secondblade hardware exhibits a second height that is less than the firstheight, and wherein the printed circuit board is located between thefirst blade hardware and the first planar portion of the pan assembly; afirst media interface module mounted on the second surface of theprinted circuit board and exposed at a front end of the blade; a secondmedia interface module mounted on the first surface of the printedcircuit board, wherein the second media interface module is exposed atthe front end of the blade; a first shim located between the first mediainterface module and the second surface of the printed circuit board,wherein the first shim positions the first media interface module inparallel with the first planar portion of the pan assembly; and a secondshim located between the second media interface module and the firstsurface of the printed circuit board, wherein the second positions thesecond media interface module in parallel with the first planar portionof the pan assembly.
 10. A blade comprising: a printed circuit boardthat extends between a front end of the blade and a distal rear end ofthe blade, wherein the printed circuit board is mounted at an anglewithin the blade, such that the printed circuit board is higher at thefront end of the blade than at the rear end of the blade; a pair ofmedia interface modules mounted on opposing surfaces of the printedcircuit board in a belly-to-belly configuration, wherein the pair ofmedia interface modules are exposed at the front end of the blade; and afaceplate located at the front end of the blade, wherein front surfacesof the pair of media interface modules are exposed through thefaceplate, wherein the front surfaces are co-planar with one another,but are not located in parallel with the faceplate.
 11. A bladecomprising: a printed circuit board that extends between a front end ofthe blade and a distal rear end of the blade, wherein the printedcircuit board is mounted at an angle within the blade, such that theprinted circuit board is higher at the front end of the blade than atthe rear end of the blade; a pair of media interface modules mounted onopposing surfaces of the printed circuit board in a belly-to-bellyconfiguration, wherein the pair of media interface modules are exposedat the front end of the blade; and a faceplate located at the front endof the blade, wherein front surfaces of the pair of media interfacemodules are exposed through the faceplate, and wherein the frontsurfaces are not co-planar with one another.
 12. A blade comprising: aprinted circuit board that extends between a front end of the blade anda distal rear end of the blade, wherein the printed circuit board ismounted at an angle within the blade, such that the printed circuitboard is higher at the front end of the blade than at the rear end ofthe blade; a pair of media interface modules mounted on opposingsurfaces of the printed circuit board in a belly-to-belly configuration,wherein the pair of media interface modules are exposed at the front endof the blade; a pan assembly including a first planar portion that formsa lower surface of the blade, wherein the angle exists between theprinted circuit board and the first planar portion of the pan assembly;and shims located between the pair of media interface modules and theprinted circuit board, wherein the shims position the pair of mediainterface modules in parallel with the first planar portion of the panassembly.